Increase in the soil nitrogen (N) availability under increasing N deposition is an important ecological process that most terrestrial ecosystems experience. Increasing N deposition could affect soil respiration and consequently, affect the soil carbon (C) and N cycling. In this study, an N deposition simulation experiment was carried out in the Cunninghamia lanceolata forest in Shixi, Taihe County, Jiangxi Province, China. Soil carbon emissions were analyzed, using an alkali absorption method, under four treatments (no N and Phosphorus (P) addition (CK), N1 addition, N2 addition, and P addition) at four different temperatures (5℃, 15℃, 25℃, and 35℃). Soil respiration was inhibited by N deposition. As the temperature increased, soil respiration increased substantially (P < 0.05). Different treatments had different effects on soil carbon emissions. The change regulation of CO₂ accumulation emission and high N change regulation were similar for P addition under different temperature conditions. At 5℃, N addition inhibited soil carbon mineralization and this effect was stronger with increasing N concentration, whereas P addition promoted the soil carbon emission with increasing N concentration. However, at 15℃ and 35℃, N and P addition had an inhibitory effect on the soil carbon emission. At higher temperatures (25℃ and 35℃), total soil carbon significantly affected the CO₂ accumulation; however, at lower temperatures (5℃ and 15℃) total soil carbon had the opposite effect on CO₂ accumulation. At 5℃, soil water content in different treatments had a significant effect on soil carbon emission, whereas the other three temperatures (15℃, 25℃, and 35℃) had no significant effect. At 25℃, soil carbon emission was significantly affected by soil DOC (P < 0.05), whereas no effect was observed at the other three soil temperatures (5℃, 15℃, and 35℃). At 25℃, soil DON had no significant effect on soil carbon accumulation emission. At 5℃, soil water content in different treatments had a significant effect on soil carbon emission but no significant effect at the other three temperatures (15℃, 25℃, and 35℃). The Q₁₀ value under N and P addition was lower than that under the control condition (no N and P addition) and the Q₁₀ value decreased with increasing N concentration. However, the difference in N deposition had no significant effect on the Q₁₀ values. The potential carbon emission from soil respiration was simulated by the single reservoir model, C_m=C_o (1-exp^-kt). The results indicated that the four treatments had a significant effect on potential soil carbon emission at 5℃, 15℃, and 35℃, but no significant effect at 25℃.